For quite some time now there have been appearances of a new type of modules drastically changing perls behaviour on CPAN. That includes new language features, new, often declarative, syntax, and changing how various built-in features behave. autobox, TryCatch, MooseX::Declare and MooseX::MultiMethods are just a few examples.
This talk will give a practical introduction to what techniques those modules use, what can be achieved with those techniques and how you can use them to do your own modifications on how perl works.
In the end, a number of interesting ideas for future development will be discussed.